Refrigerating apparatus



0a. 25, 1932. H. B. HULL 1,883,924

REFRIGERATING APPARATUS Filed May 30, 1950 INVENTOR H y a mu A JTORNEY @atented @ct. 25, 3332 HARRY RHULL, GTE DAYTGN, OHIO, ASSEGNOE TO FBIGIDAIBE COBPDRATIQN, GE DAYTGET, SE10, A CORPORATIQN OF DELAWARE BEE BIGEEATING APEABeQTUS Application filed Kay 30, 1930. Serial 2E0. 457,579.

The present invention relates to refrigerating apparatus and particularly to apparatus for returning lubricating fluid from the evaporator to the compressor of a refrigerating system of the compressor-condenser-expander type.

in a refrigerating system of the above type,

I the lubricant tends to accumulate within the evaporator and when, as in the embodiment illustrated, the liquid refrigerant is heavier than thelubricant the lubricant floats upon the top of the liquid refrigerant in the evaporator and acts as a deterrent upon evaporation. This accumulation of lubricant within the evaporator also tends to rob the compressor of necessary lubricating fluid. In order to maintain evaporating conditions sub stantially constant it is desirable to maintain the depth of the lubricant substantially con stant and below a certain maximum.

Consequently one of the objects of this invention is to maintain substantially constant and below a certain maximum the depth of the lubricating oil which floats on top of the liquid refrigerant within the evaporator.

A more general object is to provide a means for maintaining substantially constant and below a certain maximum thedepth of one liquid which floats upon the surface of a second liquid.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing Fig. 1 is a viewshowing in section a portion of an evaporator incorporating one embodiment of the invention;

Fi 2 is a view showing diagrammatically the e ements' of a refrigerating system;

Fig. 3 is a fragmentary top viewof a portion of the evaporator disclosed in Fig 1 and Fig. l is a fragmentarysectional view of an evaporator incorporating another embodiment of the invention.

The refrigerating system shown for illustrative purposes comprises a compressor 21 for compressing the refrigerant, preferably the evaporator 27 to the compressor 21, and to pressure responsive means 29 is preferably connected in the return conduit 28 for controlling the motor 24 to rovide alternating operating and idle perio s of the compressor 21 according to the temperature of the evapas orator 27.

' Thus it will be seen from the above de-= scription that the compressor 21, the condenser 22, the receiver 23, and the conduits 26 and 28 constitute means for supplying the evaporator 27 with liquid refrigerant and also for removing gaseous refrigerant from the evaporator. p

The preferred type of evaporator as dis closed in the drawing includes a tank 30 of a cylindrical form, having its one end closed by a valve plate 32, secured by bolts 33 in a supporting ring 34; surrounding the 0 ening in the tank 30 of the evaporator. he va ve plate has an outlet fitting 35 and an inlet fitting 36 supported thereon. The fittings form shut-ofi valves. The inlet fitting 36 for the liquid refrigerant enters into a passage through a boss 37 on the inner side of the valve plate. A supporting bracket 38 is atskimmer 42 is mounted on thefioat member and preferably on arm 40 near the float ball 39. 'Within the cup or skimmer 42 is an inverted l..-shaped lubricant tube 43 (Fi 1 and 3) which extends upwardly for a siort distance and then laterally towards the valve.

I lubricant tube 43 is plate 32 where it is supported by a larger outlet tube 44 which in turn is supported by the valve plate 32 and which communicates with the outlet fitting 35 by anaperture through the valve plate 32. The refri erant gas is removed from the evaporator uring operating periods of the compressor through the outlet tube 44 which has its outer end open for this purpose, and turned up 'to prevent liquid refrigerant from being removed through this tube, Adj scent the valve plate 32 there is a Venturi section in the outlet tube 44 and the lateral end of the L-shaped ositioned within the Vcnturi section 45 of t e outlet tube 44.

The position of the float mei'nber which comprises the closed non-sinlrable float ball 39 and the float ball arm 40 is determined by the level of the liquid refrigerant within the evaporator which is indicated by the reference character 46. When the level of the liquid refrigerant within the evaporator is lowered by evaporation the float member falls to a lower position and opens the needle valve which controls the flow of liquid refrigerant into the evaporator When the level of the liquid'refrigerant is raised by virtue of the needle valve being open, the float member is raised and the needle valve is closed.-

It is inevitable that a portion of the lubrieatin fluid of the compressor .will be scrubbed up through the cylinders into the condensing chamber and thus be carried into the evaporator. The lubricant, bein much li hter than the liquid refrigerant, oats as a layer or upon the surface of the liquid refrigerant as indicated by reference character 47. It is desirable to keep the depth of this layer of lubricant below a certain maximum and according to the embodiment shown in Fig. i when the depth of the layer cant within the evaporator is more than is desired the excess lubricant cup or skimmer 42. Since thecup is carried by or attached to move simultaneously with the float member the position of which is determined by the level of the liquid refrigerant by reason of the fact that the liquid refrigerant is much heavier than the lubricant, a substantially fixed distance is maintained between the level of the liquid refrigerant and the level of the lubricant, thus maintaining the depth of the layer of lubricating fluid substantially constant.

Suction through the i.-shaped tube 43 is provided by virtue of the position of the lateral end of this tube preferably within the smallest part of the Venturi section 45 and through the Venturi action the lubricant is drawn up through the L-shaped connecting tube 43 and discharged into the stream of gaseous refrigerant when it is removed from the evaporator through the outlet tube 44 and by this arrangement the lubricant is carriedback of lubrioverflows into the to the compressor where it again serves its lubricating function.

In Fig. 4 a slightly different arrangement is used to carry out the principle of the invention. In this arrangement, instead of the cup 42 and the L-shaped connecting tube 43,-

a single tube 48 is used, this tube having one end serving as a skimmer and fastened to the float member by a bracket 49 and the other end preferably directed into the smallest part of the Venturi section 50. The end of the tube which is fastened upon the float member projects vertically upward to the desired level of the lubricant indicated by the reference character 47.

A loop 51 is formed in the tube 48 for the purpose of increasing flexibility, necessitated by the fact that the one end of the tube is fastened to the movable float member. The tube 48 may be of the ordinary type which is somewhat flexible or of the so-called flexible type as is shown in Fig. 4.

The arrangement in Fig. 4'operates in a manner similar to the operation of the arrangement in Fig. 1. The float member determines the depth of the liquid refrigerant within the evaporator and the end of the tube 48 which is carried by the float member determines the level of the lubricant with respect to the level of the liquid refrigerant.

The excess lubricant"- is skimmed into and carried through the tube 48 and discharged into the stream of the aseous refrigerant and thus returned to the c mpressor.

While the form of embodiment of the invention as herein disclosed, constitutes a'preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which-follow.

What is claimed is as follows:

1. In a refrigerating system, an evaporator adapted to contain a gaseous refrigerant, a liquid refrigerant, and a layer of lubricating fluid, a float member for regulatin the level of the liquid refri erant, a duct or removing the gaseous re rigerant, and means communicatmg with said duct for removing lubricatin fluid from said evaporator, said means inclu ing a portion separate from and attached to move simultaneously with said float member.

2. In a refrigerating system, an evaporator adapted to contain a gaseous refrigerant, a liquid refrigerant, and a layer of lubricating fluid, a float member for regulating the level of the liquid refrigerant, a not for removing the gaseous refrigerant, and means communicating with said duct for maintaining the depth of said layer of lubricating fluid substantially constant, said means adapted to contain a gaseous refrigerant, a

insane;

J J I, v I I liquid refrigerant, and a layer of lubricating fiuid, a float member for regulating the level of the liquid refrigerant, a duct in. said evaporator for removing the gaseous refrigerant, and means discharging into said duct and having a portion separate from and attached to move simultaneously with said float memher for maintaining the depth of said lubrieating fluid substantially constant and for removing the excess of lubricating fluid from the evaporator. 7

a. In a refrigerating system, an evaporator adapted to contain a uantity of liquid reirigerant and a layer of ubricating fluid upon the surface of? the liquid refrigerant, a nonsinkable float member vvithin said evaporator, and means separate :troru and having a portion attached to said -sinlrable dost memher to move simultaneously therewith for maintaining the depth or? said layer of lubricating substantially constant, 7

5. In a refrigerating system, an evaporator adapted to contain a quantity of liquid re iirigerant and a layer oil lubricating i floating upon the surface oi said liquid erant, means for supplying said evaporator with said liquid refrigerant, a pivoted nonsinkable float member tor regulating said means, and a second means separate from and having a portion attached to said pivoted non-sinlrable float member to move simultaneously therewith-tor regulating the depth of said layer of lubricating fluid.

' 8. in a refrigerating system, an evaporator adapted to contain a quantity o'iliquid reirigerant and a layer or" lubricating fluid iloating upon the surface of said liquid reirigen ant, a non-sinlrable float member for regulating the level of said liquid refrigerant, and means separate from and having a portion to said non-sinlable float member to move simultaneously therewith for regulating the depth of said layer of lubricating fluid,

l. refrigerating system, an evaporator adapted to contain-a quantity of liquid refrigerent and a layer oi lubricating fluid floating upon the surface of said liquid re= irigerant, a non-sinliable float member for regulating the level of said liquid refrigerant, and means separate from and having a portion attach-ed to said non-sinlrable float mem- .ber to move simultaneously therewith for maintaining the depth oil said layer of lubrieating fluid substantially constant,

a refrigerating system, an evaporator adapted to contains quantity oi liquid reiri'gerant and a layer of lubricating fluid floating upon the surface of said liquid refrigerant, a non-sinlrable float member for regulating the level of said liquid refrigerant, and means separate from and having a portion attached to said non-sinkable float member to move simultaneomly therewith for remov tion attached to said non-sinkable float membar to move simultaneously therewith for maintaining the depth of said layer of lubrieating fiuid substantially constant and for removing the excess lubricating fluid.

10. In a refrigerating system, an evaporator adapted to contain a gaseous reiri erant, a liquid refrigerant, and a layer of in ricating fluid, means for supplying the evaporator with the liquid refrigerant and for removing said gaseous refrigerant, a valve assembly for controlling the supply of liquid refrigerant, a float member pivoted to said valve assembly, and means having a portion separate from and attached to move simultaneously with said iloat member for regulating the depth of the layer oi lubricating fluid.

11. In a refrigerating system, an evaporator adapted to contain a gaseous refrigerant, a liquid refrigerant, and a layer of lubricating fluid, means for supplying the evaporator with the liquid refrigerant and for removing said gaseous refrigerant, a valve assembly for controlling the supply of liquid refrigerant, a float member pivoted to said valve assembly, and means having a portion separate from and attached to move simultaneously with said non-sinlrable float member for maintaining the depth of said layer or lubricating fluid substantially constant.

l2. In a refrigerating system, an evaporator adapted to contain a gaseous refrigerant, a liquid refrigerant, and a layer of lubricating fluid, means for supplying the evaporator with the liquid refrigerant and for removing said gaseous refrigerant, a valve assembly for controlling the supply of liquid refrigerant, a float member pivoted to said valve assembly, and means having a portion separate from and attached to move simultaneously with said non-sinkable float member for removing said lubricating fluid from said evaporator.

13. in a refrigerating system, an evaporator adapted to contain a gaseous refrigerant, a liquid refrigerant, and a layer oilubrieating fluid, means for supplying the evaporator with the liquid refrigerant and for removing said gaseous refrigerant, a valve assembly tor controlling the supply of liquid refrigerant, a float member pivoted to said valve assembly, and means having a portion separate from and attached to move simultaneously with said, non-sinkable float memher for maintaining the deptnvoi said layer of lubricating fluid substantially constant and for removing the excess lubricating fluid,

no I

14. In a refrigerating system, an evaporator ada ted to contain a gaseous refri erant, a liquid refrigerant, and a lafyer of In ricating fluid, a non-sinkable floator re ulating the level of the liquid refrigerant, an a skimmer separate from and attached to move simultaneously with said non-sinkable float for maintaining the depth of said lubricating fluid substantially constant and for removing the excess of lubricating fluid from the evaporator. Y I

15. In a refrigerating system, an evaporator ada ted to contain a aseous refri erant, a liquid refrigerant, an a layer of ubricating fluid, means for supplying the evaporator 'with the liquid refrigerant and for removing said gaseous refrigerant a valve assembly for controlling the sup ly of liquid refrigerant, a non-sinkable oat member pivoted to said valve assembly, and means having a portion separate from and attached to move simultaneously with said non-sinkable float member for receiving said fluid and for maintaining the depth of said layer of lubricatin fluid substantially constant, said last name means also having another portion communicating with said first named means for delivering the-excess lubricating fluid collected in said second named means to said first named means in res onse to the removal of gaseous refrigerant mm the evaporator. 16. In a refrigerating system, an evaporator adapted to contain a gaseous refri erant, a

liquid refrigerant, and a layer of lu ricating fluid, means for supplying the evaporator with the liquid refrigerant and for removing said gaseous refrigerant, a valve assembly for controlling the supply of liquid refrigerant, a non-sinkable float member pivoted to said valve assembl and a flexible conduit having one of its en s attached to move simultaneously with said non-sinkable float member for receiving said fluid and for maintainingmhe depth of said layer of lubricating fluid substantially constant, said flexible conduit having' its other end communicating with said first named means for delivering the excess lubricating fluid collected in sai conduit to said first named means in response to the removal of gaseous refrigerant from the evaporator.

In testimony whereof I hereto afiix my signature. HARRY B0 HULL.

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